I actually do this! Thought I was the only one! LOL. Especially here in sunny south Florida. I pull into the garage and open the hood. Once the car is cooled off I give it a wipe down usually with a quick detailer.
Here in hot Florida, I do this if I know that I want to work on my car after work. Actually put a fan over the engine area to cool things down a bit quicker. Otherwise, it's not cool until 12 hours later lol.
Whenever customers car arrive here for a wash or detail, I may open the hood, or if you prefer bonnet to allow faster cooling so I can start my work sooner.
I just did this Saturday for a lil blue bug i was doing for a buddies daughter. Fan to the side and popped the hood while I started on the back. Nice and cool by the time I got around to the front.
Not something I normally do but I will do it after a drive home from work if I want to clean on the car before it gets dark.